The invention involves a pilot head restraint system that provides the pilot protection against severe lateral forces, but allows free movement of the pilot's head during normal flight conditions.
Modern high performance fighter aircraft are capable of sophisticated light maneuvers, including tight turning and rapid acceleration, which enable the aircraft to evade enemy missiles and rockets. However, this improved aircraft maneuverability is counterproductive if the resulting forces imposed on the unprotected pilot are beyond human tolerances. One can only speculate as to the number of fighter aircraft lost as a result of pilot blackout.
There already exist several designs, which are not effective for this purpose because of design limitations. U.S. Pat. No. 2,638,293 discloses a sophisticated head restraint system, wherein the helmet is connected to five inertia reels, which are each attached to a pulley system located behind the pilot. During any violent aircraft maneuvers, the head of the pilot is firmly restrained against the headrest. However, in this position the pilot has limited peripheral vision, and a diminished view of the instrument panel. In a combat mission, a pilot must be able to move his head quickly in any direction. Such free movement cannot be accommodated by this system. U.S. Pat. No. 4,004,763 discloses another head restraint system that requires the pilot's head to be restrained in the reclining position, which again limits head movement and pilot vision.
A head restraint system is needed that will enable free and unencumbered head movement during periods of tolerable lateral inertia forces, while locking in place and protecting the pilot's head during periods of high lateral inertia forces.